/*******************************************************************************
* Copyright (c) 2011, 2015 Oracle and/or its affiliates. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation
*
******************************************************************************/
package org.eclipse.persistence.jpa.jpql.tools.model.query;
import java.io.IOException;
import org.eclipse.persistence.jpa.jpql.Assert;
import org.eclipse.persistence.jpa.jpql.parser.FunctionsReturningStringsBNF;
import org.eclipse.persistence.jpa.jpql.parser.JPQLExpression;
import org.eclipse.persistence.jpa.jpql.parser.LiteralBNF;
import org.eclipse.persistence.jpa.jpql.parser.StringPrimaryBNF;
import org.eclipse.persistence.jpa.jpql.parser.TrimExpression;
import org.eclipse.persistence.jpa.jpql.parser.TrimExpression.Specification;
import static org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.*;
import static org.eclipse.persistence.jpa.jpql.parser.Expression.*;
/**
* The <code><b>TRIM</b></code> function trims the specified character from a string. If the
* character to be trimmed is not specified, it is assumed to be space (or blank). The optional
* <code>trim_character</code> is a single-character string literal or a character-valued input
* parameter (i.e., char or <code>Character</code>). If a trim specification is not provided,
* <code><b>BOTH</b></code> is assumed. The <code><b>TRIM</b></code> function returns the trimmed
* string.
*
* <div><b>BNF:</b> <code>expression ::= TRIM([[trim_specification] [trim_character] FROM] string_primary)</code><p></div>
*
* @see TrimExpression
*
* @version 2.5
* @since 2.4
* @author Pascal Filion
*/
@SuppressWarnings({"nls", "unused"}) // unused used for the import statement: see bug 330740
public class TrimExpressionStateObject extends AbstractSingleEncapsulatedExpressionStateObject {
/**
* Defines the way the string is trimmed.
*/
private Specification specification;
/**
* The trim character, if specified.
*/
private StateObject trimCharacter;
/**
* Notifies the visibility of the <code><b>FROM</b></code> identifier has changed.
*/
public static final String HAS_FROM_PROPERTY = "hasFrom";
/**
* Notifies the specification property has changed.
*/
public static final String SPECIFICATION_PROPERTY = "specification";
/**
* Notify the state object representing the trim character has changed.
*/
public static final String TRIM_CHARACTER_PROPERTY = "trimCharacterStateObject";
/**
* Creates a new <code>TrimExpressionStateObject</code>.
*
* @param parent The parent of this state object, which cannot be <code>null</code>
* @exception NullPointerException The given parent cannot be <code>null</code>
*/
public TrimExpressionStateObject(StateObject parent) {
super(parent);
}
/**
* Creates a new <code>TrimExpressionStateObject</code>.
*
* @param parent The parent of this state object, which cannot be <code>null</code>
* @param stateObject The {@link StateObject} representing the encapsulated expression
* @param specification Defines the way the string is trimmed, or {@link
* org.eclipse.persistence.jpa.jpql.parser.TrimExpression.Specification#DEFAULT
* Specification.DEFAULT} when it is not present
* @exception NullPointerException The given parent cannot be <code>null</code>
*/
public TrimExpressionStateObject(StateObject parent,
Specification specification,
StateObject stateObject) {
this(parent, specification, null, stateObject);
}
/**
* Creates a new <code>TrimExpressionStateObject</code>.
*
* @param parent The parent of this state object, which cannot be <code>null</code>
* @param specification Defines the way the string is trimmed, or {@link
* org.eclipse.persistence.jpa.jpql.parser.TrimExpression.Specification#DEFAULT
* Specification.DEFAULT} when it is not present
* @param trimCharacter The trim character
* @param stateObject The {@link StateObject} representing the encapsulated expression
* @exception NullPointerException The given parent cannot be <code>null</code>
*/
public TrimExpressionStateObject(StateObject parent,
Specification specification,
StateObject trimCharacter,
StateObject stateObject) {
super(parent, stateObject);
this.specification = specification;
this.trimCharacter = parent(trimCharacter);
}
/**
* Creates a new <code>TrimExpressionStateObject</code>.
*
* @param parent The parent of this state object, which cannot be <code>null</code>
* @param jpqlFragment The portion of the query representing the encapsulated expression
* @exception NullPointerException The given parent cannot be <code>null</code>
*/
public TrimExpressionStateObject(StateObject parent, String jpqlFragment) {
super(parent, jpqlFragment);
}
/**
* {@inheritDoc}
*/
public void accept(StateObjectVisitor visitor) {
visitor.visit(this);
}
/**
* {@inheritDoc}
*/
@Override
public TrimExpression getExpression() {
return (TrimExpression) super.getExpression();
}
/**
* {@inheritDoc}
*/
@Override
public String getIdentifier() {
return TRIM;
}
/**
* {@inheritDoc}
*/
@Override
protected String getQueryBNFId() {
return StringPrimaryBNF.ID;
}
/**
* Returns the new trim specification.
*
* @return The new trim specification; which is never <code>null</code>
*/
public Specification getSpecification() {
return specification;
}
/**
* Returns the {@link StateObject} representing the trim character.
*
* @return The {@link StateObject} representing the trim character or <code>null</code> if it is
* not present
*/
public StateObject getTrimCharacter() {
return trimCharacter;
}
/**
* Determines whether the way the trim is trimmed was parsed.
*
* @return <code>true</code> if the query contained the way the trim needs to be trimmed;
* <code>false</code> otherwise
*/
public boolean hasSpecification() {
return (specification != Specification.DEFAULT);
}
/**
* Determines whether the character used to trim the string was specified.
*
* @return <code>true</code> if the character used for trimming was specified; <code>false</code>
* otherwise
*/
public boolean hasTrimCharacter() {
return trimCharacter != null;
}
/**
* {@inheritDoc}
*/
@Override
public boolean isEquivalent(StateObject stateObject) {
if (super.isEquivalent(stateObject)) {
TrimExpressionStateObject trim = (TrimExpressionStateObject) stateObject;
return specification == trim.specification &&
areEquivalent(trimCharacter, trim.trimCharacter);
}
return false;
}
/**
* {@inheritDoc}
*/
@Override
public void parse(String jpqlFragment) {
StringBuilder sb = new StringBuilder();
sb.append(TRIM);
sb.append(LEFT_PARENTHESIS);
sb.append(jpqlFragment);
sb.append(RIGHT_PARENTHESIS);
JPQLExpression jpqlExpression = new JPQLExpression(
sb,
getGrammar(),
FunctionsReturningStringsBNF.ID,
true
);
TrimExpression trimExpression = (TrimExpression) jpqlExpression.getQueryStatement();
setSpecification(trimExpression.getSpecification());
parseTrimCharacter(trimExpression.getTrimCharacter().toParsedText());
super.parse(trimExpression.getExpression().toParsedText());
// The trim character is actually the string primary
if (!hasStateObject() && hasTrimCharacter()) {
setStateObject(new StringLiteralStateObject(this, trimCharacter.toString()));
trimCharacter = null;
}
}
/**
* Parses the given JPQL fragment, which represents either a single-character string literal or a
* character-valued input parameter, the fragment will be parsed and converted into a {@link
* StateObject}.
*
* @param jpqlFragment The portion of the query to parse
*/
public void parseTrimCharacter(CharSequence jpqlFragment) {
StateObject stateObject = buildStateObject(jpqlFragment, LiteralBNF.ID);
setTrimCharacter(stateObject);
}
/**
* Removes the trim specification.
*/
public void removeSpecification() {
setSpecification(Specification.DEFAULT);
}
/**
* Removes the trim character if it is defined.
*/
public void removeTrimCharacter() {
setTrimCharacter(null);
}
/**
* Keeps a reference of the {@link TrimExpression parsed object} object, which should only be
* done when this object is instantiated during the conversion of a parsed JPQL query into
* {@link StateObject StateObjects}.
*
* @param expression The {@link TrimExpression parsed object} representing a <code><b>TRIM</b></code>
* expression
*/
public void setExpression(TrimExpression expression) {
super.setExpression(expression);
}
/**
* Sets the new trim specification.
*
* @param specification The new trim specification; <code>null</code> is not valid
*/
public void setSpecification(Specification specification) {
Assert.isNotNull(specification, "The Specification cannot be null");
Specification oldSpecification = this.specification;
this.specification = specification;
firePropertyChanged(SPECIFICATION_PROPERTY, oldSpecification, specification);
}
/**
* {@inheritDoc}
*/
@Override
public void setStateObject(StateObject stateObject) {
super.setStateObject(stateObject);
}
/**
* Sets the character to trim from the string. If the character to be trimmed is not specified,
* it is assumed to be space (or blank). It is a single-character string literal or a character-
* valued input parameter (i.e., char or <code>Character</code>).
*
* @param trimCharacter The trim character or <code>null</code> to remove it
*/
public void setTrimCharacter(StateObject trimCharacter) {
StateObject oldTrimCharacter = this.trimCharacter;
this.trimCharacter = parent(trimCharacter);
firePropertyChanged(TRIM_CHARACTER_PROPERTY, oldTrimCharacter, trimCharacter);
}
/**
* {@inheritDoc}
*/
@Override
protected void toTextEncapsulatedExpression(Appendable writer) throws IOException {
// Specification
if (specification != Specification.DEFAULT) {
writer.append(specification.name());
writer.append(SPACE);
}
// Trim character
if (hasTrimCharacter()) {
trimCharacter.toString(writer);
writer.append(SPACE);
}
// FROM
if ((specification != Specification.DEFAULT) || hasTrimCharacter()) {
writer.append(FROM);
writer.append(SPACE);
}
// String primary
super.toTextEncapsulatedExpression(writer);
}
}